Sleep and athletic performance: How better sleep improves recovery and results

Quick answer: How does sleep affect athletic performance?

Sleep improves physical performance by supporting recovery, muscle growth, reaction time, focus, learning, motivation and injury prevention. Research suggests athletes who regularly get less than seven hours of sleep per night face a significantly greater risk of injury and reduced performance, while increasing sleep duration can improve recovery and cognitive function.

Why sleep is one of the most important performance tools

For endurance and hybrid athletes, including those training for HYROX, sleep is particularly important. The combination of running volume, strength training and spurts of high-intensity places significant recovery demands on the body. Consistent, high-quality sleep helps support adaptation between sessions and prepares you to perform at your best on race day.

According to Dr Meeta Singh, a sleep consultant for multiple NFL, MLB, NHL, NBA, Olympic, and college sports teams,  sleep influences far more than how energetic you feel when you wake up.

"Sleep is essential for all aspects of athletic performance, including optimal reaction times, accuracy, optimal motor function, focus, motivation, glucose metabolism, memory and learning, as well as stress regulation, all of which are integral for athletic performance," says Dr Singh.

Sleep is also closely tied to your body's circadian rhythms, the internal biological clocks that help regulate key physiological functions.

These circadian rhythms influence:

• Muscle strength
• Reaction time
• Flexibility
• Recovery
• Muscle growth and maintenance

As Dr Singh explains: "I like to think of sleep as a circuit board with one switch, and if that switch fails, everything else will also break down."

For athletes and exercisers alike, sleep provides the foundation that allows physical training to translate into performance improvements. Beyond its impact on day-to-day performance, sleep may also play a critical role in helping athletes stay healthy enough to train consistently.

Sleep and injury prevention

One of the most compelling reasons to prioritize sleep is its impact on injury risk. When researchers examined the consequences of inadequate sleep, they uncovered a striking finding: consistently sleeping fewer than seven hours per night may almost double the risk of musculoskeletal injury.

This has significant implications for anyone training regularly. Injuries don't just impact performance. They disrupt consistency, delay progress, and often require weeks or months of rehabilitation.

The findings reinforce the idea that sleep should be viewed as an essential component of any training program, just like strength training, conditioning, nutrition and recovery.

What happens during sleep that improves performance?

Sleep is often thought of as downtime. In reality, it's an active period of restoration and repair.

Dr Singh adds: "Sleep allows for psychological, physiological and physical recovery. It is really providing recovery at the cellular level."

While you sleep:

• Physical recovery takes place
• Energy stores are replenished
• The brain processes information and learning
• Mental recovery occurs
• Restorative physiological processes are activated

Dr Singh describes one particularly fascinating process: "We now know that during sleep, the brain gets cleansed of waste material, akin to being power washed."

This combination of physical and cognitive recovery helps explain why sleep is so tightly linked to training outcomes.

Sleep or exercise: which should come first?

It's a question many active people wrestle with. Should you sacrifice sleep to squeeze in an early-morning workout? According to Dr Singh, both sleep and exercise are essential, but sleep is the biological necessity.

"Exercise has tremendous health benefits, but sleep is a biological need that is essential for overall health,” says Dr Singh. “If the choice was between getting regular sleep or getting regular exercise, I would say sleep gets precedence."

Her advice is simple:

• Prioritize seven to nine hours of sleep
• Schedule exercise so it doesn't compromise sleep
• Work with your natural chronotype rather than against it – if you’re a night owl, don’t try to wake up and exercise at the crack of dawn

The ultimate goal isn't choosing sleep or exercise. It's finding a routine that supports both.

Can more sleep improve sports performance?

Yes. Research shows that extending sleep by approximately 30 minutes per night over several days can improve reaction time and cognitive performance in athletes.

An extra 30 minutes of sleep can make a significant difference

The research involving professional baseball players tested what would happen if athletes increased their nightly sleep by approximately 30 minutes over five consecutive nights. The findings were impressive. The athletes improved their reaction times significantly, which can have a massive impact on sporting success.

It’s not just professional sports people who can benefit from more shuteye. Many people live in a state of mild sleep deprivation. Even modest increases in sleep duration may improve:

• Alertness
• Focus
• Mood
• Cognitive performance
• Recovery

As Dr Singh notes: "Adding even half an hour extra helps, and we should never underestimate the power of a 20-minute nap."

Are naps good for athletes?

Naps can be an effective tool when you're unable to consistently achieve seven to nine hours of sleep overnight.

According to Dr Singh, napping can help reduce accumulated sleep debt and provide a performance boost when used appropriately.

However, naps are not appropriate for everyone. Napping may reduce sleep drive, making it harder to fall asleep at night. "If you have problems falling asleep or staying asleep at night despite adequate opportunity to sleep, then napping is not a good idea," adds Dr Singh. She also advises caution regarding timing. Waking from a nap can result in temporary grogginess, so it's best to avoid scheduling naps immediately before important performance or work demands.

Dr Nic Gill, Vice President of Health and Performance for the Baltimore Ravens, is a huge advocate of napping. He says people consistently underestimate the impact of good-quality sleep on performance, recovery, energy, and overall health, noting that a short nap can work wonders. Dr Gill shares more about what everyday exercisers can learn from high performance athletes here.

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How many hours of sleep do athletes need?

Most adults need seven to nine hours of sleep per night. Athletes undertaking high training loads may benefit from being towards the upper end of that range to support recovery, performance and adaptation.

According to Dr Singh, one of the best ways to establish your true sleep needs is to remove artificial constraints.

She recommends:

• Choosing a consistent bedtime
• Eliminating alarm clocks where possible
• Maintaining the same sleep schedule for two weeks
• Allowing the body to wake naturally

Initially, you may sleep longer as your body repays accumulated sleep debt. Eventually, most people settle into a consistent rhythm that reveals their genuine sleep requirement.

What matters most: quantity, quality or timing?

According to Dr Singh, all three matter. However, quantity comes first. "Adults need seven to nine hours, and if you get less than six hours of sleep, you're likely to be impacted."

The second priority is quality. Good-quality sleep generally means:

• Falling asleep within 30 minutes
• Sleeping soundly through the night
• Experiencing no more than one awakening
• Returning to sleep quickly if you wake

Timing is the third component. Ideally, sleep should align with your biological clock and occur at consistent times each day.

Six expert tips for sleeping smarter

1. Keep your bedroom cool, dark and comfortable. Small environmental adjustments can significantly improve sleep quality.
2. Be consistent. Try to go to bed and wake up at the same time every day, including weekends.
3. Avoid stimulants before bedtime. Limit caffeine, nicotine and alcohol close to bedtime, as each can negatively affect sleep quality.
4. Avoid excessive food and fluids at night. Heavy meals and excessive fluid intake can interrupt sleep.
5. Stop watching the clock. Constantly checking the time during the night can increase stress and make it harder to return to sleep.
6. Avoid naps if you struggle to sleep at night. Naps may interfere with nighttime sleep for some individuals.

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Science-backed sleep tip: Try a bedtime workout that promotes relaxation‍

Research shows just 30 minutes of BODYBALANCE™ in the evening can help you shed stress, relax more and sleep better. You can access BODYBALANCE sessions anytime, anywhere using the LES MILLS+ app.

The bottom line

Sleep is one of the most effective performance enhancers available, yet it's often the most overlooked. Better sleep supports recovery, muscle growth, learning, reaction time, focus and injury prevention. Research suggests that consistently sleeping fewer than seven hours per night may increase injury risk, while even modest increases in sleep duration can improve performance outcomes.  

Whether you're training for a HYROX event, building strength in the gym or simply aiming to get more from your workouts, making sleep a priority may be one of the smartest training decisions you can make.

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Related reading

The science of sleep: How sleep and exercise work together for better health
Discover how sleep influences recovery, longevity, weight management and overall wellbeing.

Strength training and sleep: Why lifting helps you sleep better
Research reveals why resistance exercise may be one of the most effective workouts for better sleep.

HIIT and sleep: Finding the sweet spot for better recovery
Learn how much high-intensity exercise supports better sleep, mood and recovery.

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Dr Meeta Singh is the Service Chief of Sleep Medicine and Medical Director at the Henry Ford Sleep Laboratory in Michigan where her work and research focuses on helping maximize performance in individual athletes and sports teams. She has served as a consultant for multiple NFL, MLB, NHL and NBA teams and worked with college sports teams to address sleep deprivation and jet lag and maximizing athletic performance. She also works with C-suite executives to help with jetlag management and enhancing sleep. Dr Singh is board-certified by the American Board of Psychiatry and Neurology as a Psychiatrist and Sleep Medicine subspecialist, and is a member of the American Academy of Sleep Medicine the Sleep Research Society.

Follow Dr Singh at LinkedIn or on Twitter @athletesleepmd1